I came across a Wikipedia article titled "Urine diversion". It explains different ways, including using special diversionary toilets, and treating the collection of human feces and urine separately as opposed to just flushing everything down the toilet, maybe something most people in well developed countries are used to. These sentences caught my attention:
Separate treatment of the two types of waste is justified since urine is nearly sterile and low in pathogens, provided an individual is healthy. This means that urine can be readily utilized as a fertilizer or discharged with less risk to community.
Human feces, on the other hand are high in pathogens, including up to 120 viruses and need to be treated well before it can be safely used in agriculture.
Urine diversion - principle (Wikipedia article)
So urine is nearly sterile and low in pathogens, however it qualifies that statement with the condition that the person producing that urine is healthy. I assume when they compare this to feces they do so with all other things being equal (ie., provided an individual is healthy).
It claims that there may be up to 120 viruses in feces, as opposed to urine which it characterizes as being relatively low risk. I assume that feces are riskier in transmission of diseases because it naturally contains more pathogens, but it doesn't explain what these viruses or pathogens are. I was wondering if someone could elaborate on the risks of feces over urine, and also, notwithstanding that it says that urine is relatively low-risk, what health issues can be caused by reusing urine.